Reaction propelled bulb for drawing lines through conduits



2,966,337 FOR DRAWING DU Dec. 27, 1960 R. s. KNAPP REACTION PROPELLEDBULB LINES THROUGH CON ITS Filed June 16, 1958 INVENTOR. e5. 5 62a,;

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United States Patent REACTION PROPELLED BULB FOR DRAWING LINES OUGHCONDUITS Robert S. Knapp, St. Louis, Mo., assignor to Knapp- MonarchCompany, St. Louis, Mo., a corporation of Delaware Filed June 16, 1958,Ser. No. 742,337

3 Claims. (Cl. 254-1343) This invention relates to a jet line bulb cap,particularly designed for low cost of manufacture and elficiency ofoperation in the control of a jet line attached to a Sparklet bulb whensuch bulb is used in a jet line gun of the type shown in Hensley et al.,Patent 2,930,584.

A jet line gun is one which is directed into an electrical conduit orthe like and punctures a Sparklet bulb to which a jet line of nylon orthe like is secured, whereupon the bulb is jet-propelled from the gunand through the conduit, around any bends or curves therein, and finallyexits from the opposite end of the conduit, having carried the line withit from a container of line so mounted as to permit paying out of theline therefrom. The nylon line then enables fish wires, electric wiresand the like to be placed within the conduit. Before my invention, thejet line was kept from slipping olf the neck of the bulb by means of aspecial metal ring which was pressed on, or otherwise secured to, thebulb after the bulb was filled with CO or other gas under pressure and acap welded on it.

One object of my invention is to eliminate the special ring and theoperation required for assembling it to the bulb, and I provide a bulbcap larger in diameter than the bulb neck so that when the cap is weldedin position it will serve as an enlargement to prevent the line fromslipping off the neck of the bulb without the necessity of furthermanufacturing operations on the bulb.

Another object is to provide a special bulb cap preferably of the typeshown in the Kochner Patent No. 2,685,383 of August 3, 1954, wherein thecap is provided with a flange-like enlargement or retaining flange toserve the purpose of holding the line from slipping off the bulb neck.

-A further object is to provide the retaining flange of special shape(with one or more notches) to protect the jet line as the bulb passesaround curves and corners in the electrical conduit, thus minimizing thepossibility of severing the line by impact of the outer edge of theflange against the conduit with the line between the two.

Still a further object is to provide a plurality of such notches tominimize the circumferential extent of the retaining flange and insurethat the jet line will seek one of the notches as the bulb rounds acurve or turns a corner in the conduit, thus preventing fraying andseverance of the line.

With these and other objects in view, my invention consists in theconstruction, arrangement and combination of the various parts of my jetline bulb cap, whereby the objects above contemplated are attained, ashereinafter more fully set forth, pointed out in my claims andillustrated in detail on the accompanying drawing wherein:

Fig. 1 is a side elevation of a jet line gun of the type herein referredto, a portion thereof being broken away and a Sparklet bulb with my jetline bulb cap thereon shown in the gun ready for firing, a jet linebeing associated with the gun and the bulb in the manner they arenormally used;

Fig. 2 is a sectional view through a straight section of a conduitshowing the bulb being propelled therealong by jet action and carryingthe line with it;

Fig. 3 is a similar sectional view of a curved section of conduitshowing by dotted lines the bulb negotiating the curve and by solidlines the position it takes thereafter;

Fig. 4 is an enlarged bottom plan view of a jet line bulb cap embodyingmy invention;

Fig. 5 is a perspective view thereof;

Fig. 6 is a side elevation of the cap resting on the neck of a bulbpreparatory to being welded, the bulb being shown partially in crosssection; and

Fig. 7 is a similar view entirely in section as taken on the line 7-7 ofFig. 4 and showing the welding operation completed.

On the accompanying drawing I have used the reference character G toindicate in general a jet line gun, B a Sparklet bulb and C my captherefor. The gun G has a barrel 10 to receive the bulb B and a piercingpin 12 for puncturing the same so as to release the gas therefrom andthus permit the bulb to be jet-propelled from the barrel 10 and througha conduit or the like 21. Suitable mechanism is provided for actuatingthe piercing pin 12 under control of a trigger 14 but forms no part ofmy present invention, being instead the subject matter of theabove-mentioned copending applications.

The cap C may be of the same general type shown in the Kochner PatentNo. 2,685,383, formed by cold heading" or cold forging as disclosedtherein. It is illustrated as being cup-shaped having a relatively thinwall 18 adapted to be pierced by the piercing pin 12 when the bulb isintroduced into the gun G and the piercing pin is operated by thetrigger 14. The cup is further defined by an annular wall 20 which isrelatively thick as shown in Fig. 7. The cap C is formed by a coldheading operation from wire stock of suitable size and the cold heading0r forging dies form the relatively thick wall 20 as Well as therelatively thin wall 18. They also form a flange 22 around the walls 18and 20 as illustrated and additionally form spacing projections 24 onthe bottom of the flange 22 and 26 on the outside of the wall 20.

When the cap C is placed in the neck 28 of the bulb B as shown in Fig.6, the projections 24 space the flange 22 from the upper end of the neck28 as shown by the dimension 30. At the same time the projections 26space the annular wall 18 from the interior of the neck 28 equally allthe way around the wall and neck as shown by the dimension 31. Thus, theprojections 24 and 26 cooperate to provide suitable passage for thecharging gas from a pressure chamber as illustrated in said Kochnerpatent and also in Tomasek et al., Patent No. 2,481,042 which isdirected to apparatus for charging these bulbs.

After the desired quantity of gas under pressure has been introducedinto the bulb B, the gas is cut off and the cap C is welded by passing awelding current through the cap and bulb. This heats the contactingparts (upper end of neck 28 and lower surfaces of projections 24) sothat they, under further pressure and movement toward each other, arewelded together, the bottom of the flange 22 finally engaging the upperend of the neck 28 and the welding operation being completed between thelower surface of the flange and the neck 28 so that in effect the capand bulb become integral as indicated by the cross sectioning in Fig. 7.During the welding operation the projections 26 serve the furtherpurpose of keeping the cap C centered in relation to the neck of thebulb.

At a plurality of points (four as illustrated on drawings) the flange 22is enlarged as indicated at 22a or, explained differently, I provide aflange of the diameter indicated by the projections 22a and notch it atfour points, the notches being indicated 22b. The outer edges of thesenotches are preferably rounded. The total di ameter of the portions 22ais preferably intermediate the diameter of the neck 28 and the diameterof the bulb B indicated at c, a and b respectively in Fig. 2. Thus, theprojections 22a serve as an effective means to prevent the jet line 18tied at 20 to the neck 28 from coming olf the neck during thejet-propulsion of the bulb as in Fig. 2 wherein the issuing jet-of gasis indicated 32. One of the notches 22b will receive the line during thetravel of the bulb through the conduit 22 because of the tension on theline produced by the necessity of unfurling it from the container 16.

When the bulb B enters a curve 21a of the conduit 21 as shown by dot-tedlines in Fig. 3, it of course follows the curve, and when it reaches thesolid line position it is jerked away from the outside wall of the curveby the resistance of the line (solid line showing) at which time theflange of the cap might pinch the line between the flange and the wallof the conduit. With my cap C, however, the line seeks a notch 22b ofthe flange so as to extend therethrough instead of being frayed or cutby the peripheral edge of the flange.

From the foregoing specification it will be obvious that I have provideda bulb cap particularly designed for jet line operation, and my cap, inaddition to serving as a cap for the bulb, serves as an enlargement toprevent the line from slipping off the neck of the bulb and at the sametime as a guide means for the neck end of the bulb during itsjet-propulsion along the conduit. The cap is of such character that thejet line is protected against fraying and cutting or severing by beingpinched between the flange and the conduit. The rounding of the outeredges of the notches 22b facilitates entry of the line into a notch 22aof the cap during the jet-propulsion of the bulb through the conduit 21and around curves 21a thereof. At the same time the type of capdisclosed eliminates the necessity of an additional part and anadditional operation such as used prior to my invention, and thusreduces the cost of a jet bulb for jet line gun operation.

Some changes may be made in the construction and arrangement of theparts of my jet line bulb cap without departing from the real spirit andpurpose of my invention and it is my intention to cover by my claims anymodified forms of structure or use of mechanical equivalents which mayreasonably be included within their scope.

I claim as my invention:

1. A compressed-gas-driven device adapted for drawing a line throughconduits or the like, said device comprising, in combination: anelongated hollow bulb having a reduced neck at one end thereof; and acap member welded to the terminus of the bulbs neck for sealing thebulb, said cap member having a disc-like portion which includes arelatively thin, puncturable, part that bounds the space enclosed withinsaid bulb, and an annular flange part that lies in a plane normal to thelongitudinal axis of the bulb and that extends radially outwardly of theneck of the bulb to serve, in part, as a bumper when the device is beingprojected through a conduit or the like, the portion of the flange partlocated outwardly of the neck of the bulb being notched axially toprovide a plu rality of axially extending passageways through saidflange part, and the outermost portions of said flange adjacent thenotches being rounded to define rounded entrance corners at theentrances to said notches.

2. A compressed-gas-driven device adapted for drawing a line throughconduits or the like, said device comprising, in combination: anelongated hollow bulb having a reduced neck at one end thereof; a capmember welded to the terminus of the bulbs neck for sealing the bulb,said cap member having a disc-like portion which includes a relativelythin, puncturable, part that bounds the space enclosed within said bulb,and an annular flange part that lies in a plane normal to thelongitudinal axis of the bulb and that extends radially outwardly of theneck of the bulb to serve, in part, as a bumper when the device is beingprojected through a conduit or the like, the portion of the flange partlocated outwardly of the neck of the bulb being notched axially toprovide a plurality of axially extending passageways through said flangepart; and an elongated line secured at one end thereof to said bulb andextending through one of said axial notches in the flange part of thecap member, to trail from the bulb as the bulb is driven through aconduit or the like.

3. A compressed-gas-driven device for drawing a line through conduits orthe like, said device comprising, in combination: acompressed-gas-containing bulb having a reduced neck at one end of thebulb and a puncturable cap member connected to the neck to seal thebulb, a line secured to the bulb, and bumper means to protect the linefrom fraying and severance, as the bulb is reactionpropelled through aconduit or the like by escape of the compressed gas from within the bulbafter said cap member is punctured, said bumper means including adisc-like flange means connected to the neck on said bulb, said flangemeans being of greater diameter than the diameter of said neck, theouter periphery of said flange means serving as a bumper and having aplurality of axially extending notches therein to permit passage of saidline, from the point of securance of the line to said bulb, rearwardlythrough one of said notches.

References Cited in the file of this patent UNITED STATES PATENTS1,692,710 Spahn Nov. 20, 1928 1,702,532 Boomer Feb. 19, 1929 2,425,448Weida Aug. 12, 1947 2,546,566 Schweizer Mar. 27, 1951 2,685,383 KochnerAug' 3, 1954

